Prospective Cohort Study of the Safety of an Influenza A(H1N1) Vaccine in Pregnant Chinese Women

ABSTRACTTo monitor and evaluate the safety of the influenza A(H1N1) vaccine in pregnant women and its influence on the fetus and neonate, we performed a prospective study in which 122 pregnant Chinese women who received the influenza A(H1N1) vaccine and 104 pregnant women who did not receive any vaccine (serving as controls) were observed. The results indicated that the seroconversion rate in the vaccinated group was 90.4% (95% confidence interval [CI], 82.6% to 95.5%). The rate of adverse events following immunization in the pregnant women who received the influenza A(H1N1) vaccine was 3.3%. The spontaneous abortion rates in the vaccinated group and the unvaccinated group were 0.8% and 1.9%, respectively (exact probability test,P= 0.470), the prolonged-pregnancy rates were 8.2% and 4.8%, respectively (χ2= 1.041,P= 0.308), the low-birth-weight rates were 1.6% and 0.95%, respectively (exact probability test,P= 1.000), and the spontaneous-labor rates were 70.5% and 75%, respectively (χ2= 0.573,P= 0.449). All newborns who have an Apgar score of ≥7 are considered healthy; Apgar scores of ≥9 were observed in 38.5% and 57.7% of newborns in the vaccinated group and the unvaccinated group, respectively (χ2= 8.274,P= 0.004). From these results, we conclude that the influenza A(H1N1) vaccine is safe for pregnant women and has no observed adverse effects on fetal growth. (This study has been registered at ClinicalTrials.gov under registration no. NCT01842997.)

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Glucocorticoid: Major Factor for Reduced Immunogenicity of 2009 Influenza A (H1N1) Vaccine in Patients with Juvenile Autoimmune Rheumatic Disease

The Journal of Rheumatology ◽

10.3899/jrheum.110721 ◽

2011 ◽

Vol 39 (1) ◽

pp. 167-173 ◽

Cited By ~ 39

Author(s):

NADIA E. AIKAWA ◽

LUCIA M.A. CAMPOS ◽

CLOVIS A. SILVA ◽

JOZELIO F. CARVALHO ◽

CARLA G.S. SAAD ◽

...

Keyword(s):

Rheumatic Disease ◽

Influenza A ◽

Seroconversion Rate ◽

Geometric Mean ◽

Healthy Controls ◽

Seroprotection Rate ◽

H1n1 Vaccine ◽

Link Type ◽

Autoimmune Rheumatic Disease ◽

Influenza A H1n1

Objective.To assess the immunogenicity and safety of non-adjuvanted influenza A H1N1/2009 vaccine in patients with juvenile autoimmune rheumatic disease (ARD) and healthy controls, because data are limited to the adult rheumatologic population.Methods.A total of 237 patients with juvenile ARD [juvenile systemic lupus erythematosus (JSLE), juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), juvenile scleroderma, and vasculitis] and 91 healthy controls were vaccinated. Serology for anti-H1N1 was performed by hemagglutination inhibition assay. Seroprotection rate, seroconversion rate, and factor-increase in geometric mean titer (GMT) were calculated. Adverse events were evaluated.Results.Age was comparable in patients and controls (14.8 ± 3.0 vs 14.6 ± 3.7 years, respectively; p = 0.47). Three weeks after immunization, seroprotection rate (81.4% vs 95.6%; p = 0.0007), seroconversion rate (74.3 vs 95.6%; p < 0.0001), and the factor-increase in GMT (12.9 vs 20.3; p = 0.012) were significantly lower in patients with juvenile ARD versus controls. Subgroup analysis revealed reduced seroconversion rates in JSLE (p < 0.0001), JIA (p = 0.008), JDM (p = 0.025), and vasculitis (p = 0.017). Seroprotection (p < 0.0001) and GMT (p < 0.0001) were decreased only in JSLE. Glucocorticoid use and lymphopenia were associated with lower seroconversion rates (60.4 vs 82.9%; p = 0.0001; and 55.6 vs 77.2%; p = 0.012). Multivariate logistic regression including diseases, lymphopenia, glucocorticoid, and immunosuppressants demonstrated that only glucocorticoid use (p = 0.012) remained significant.Conclusion.This is the largest study to demonstrate a reduced but adequate immune response to H1N1 vaccine in patients with juvenile ARD. It identified current glucocorticoid use as the major factor for decreased antibody production. The short-term safety results support its routine recommendation for patients with juvenile ARD. ClinicalTrials.gov; NCT01151644.

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